OK, here goes my first post, I wasn't sure whether to post here or elsewhere. I will try to be as brief as possible, but I am known for rambling on a bit.

Also, bear in mind I have done a LOT of research into this (as well as free energy stuff), I am good with electrics, OK with electronics & good at engineering (I won't go into my history here). But I have NEVER built an HHO cell before.

My Latest Project(not started yet)

I want to make 3 HHO cells, one for my car, one for my dad's car & one for a workshop blow torch (instead of oxy-acetylene).

My dad's car
is a Peugeot with a basic turbo-diesel engine (not modern HDI, but old fashioned mechanical injection). It has little room under the bonnet, so I wanted to make a dry cell for this one. He has enough money to fund the project.

My car
is a 1984 BMW 525e (known in USA as 528e). It has electronic fuel injection, but does NOT have a lambda sensor, just a basic air flow meter (MAF sensor), which is easy enough to hack but I will probably run a bypass tube with a control valve to let some of the intake air in around the sensor to trick it into running leaner.
This car has lots of spare room under the bonnet, but I don't really have enough money to fund this project.

The workshop
needs a good size torch for welding (& perhaps cutting, but I believe I will still need an oxygen bottle for this). I will be using my DC TIG/ARC welder as power for this, which gives out around 13-20volts from 10-150amps.
But let's not get bogged down too much on the workshop thing (I won't have the money for a while anyway).

Dry cell for my dad's car;
about 6" square plates (hopefully bigger), Renault Clio expansion tank as the electrolyte vessel (cheapest I could find on eBay, whatever I use will be a small car expansion vessel), probably will have 6 or 7 "cells" (gaps) per side & 2 sides, so (-nnnnn+nnnnn-) (IE: keep it to around 2v per gap), neoprene rubber gasket or large O-rings (??) between plates & I will paint some kind of insulating varnish around the holes to help avoid current bypassing. 6mm (1/4") hose inlets 8mm (5/16") outlets (one of each on each end, so 4 in total) in clear PVC pipe with nylon or PVC pipe fittings. Ends of cell will be plastic (probably commercial kitchen chopping boards) & I don't intend to pass the bolts through the cell plates (don't see the point).
I will use one bubbler next to tank, followed by a water separator, then a home made flashback arrestor close to intake (made using 2 fish tank stones inside short length of metal pipe with bronze wool packed between the air-stones).
I guess on turbo cars it's best to connect on the low pressure side, IE into the air filter box??? I've also heard horror stories of flashbacks in the air intercooler, caused by the cold start glow plugs causing damage? Any pointers on turbo diesel systems which run glow plugs on start-up?? (I really don't want to blow my dad's car up).

My car cell:
As I have more room to play with I would like to try something a little different. I would like to use a "battery of flooded wet cells" design, using 6 tubes of 1.5"-2" diameter, 6"-8" length, but still using a permanently connected electrolyte tank, like the dry cell designs. So 6 sealed pipes with electrodes inside (electrically connected between cells in series) with hose inlets at the bottom & outlets on the top, all going up to a tank of electrolyte, possibly with a circulation pump. (might cascade the pipes through the cells, but either way the cells will be completely flooded & share a common tank/bubbler like the dry cells).

My original idea was to use household plastic waste pipe (solvent weld or push-fit???) with stainless steel mesh electrodes wound round like a spiral inside the tubes (obviously with some form of spacers to keep them from touching, maybe nylon strimmer line???). But I couldn't find any suitable mesh which was 316 or 316L, only 304L grade.

So I thought why not use stainless steel tube to contain the cell but also act as one of the electrodes. So I would use some 42mm stainless tube (as outer electrode & cell wall) about 6-8" in length, with some 1.25" tube inside, giving me a 3.3mm electrode gap all round. The outer tube would be finished off each end with plastic household waste fittings (UK 1.5" waste pipe is 42mm diameter) & the inner tube electrode would be about 2" longer so I could drill & tap stainless bolts (ends ground to a point) through the plastic fittings each end, which would hold the inner electrode in place & form the electrical connection to it. But, the stainless tube isn't cheap & trying to seal all those holes & line it all up would be a pain, so I'm now thinking of just going ahead with the 304L mesh inside plastic tubes (does 304L work OK???).

Whatever design I go with I would have 6 of these pipe cells electrically joined together in series (2v per cell) & either pipe the 6 inlets & 6 outlets into the tank or cascade them through each other (or a combination of the 2, say cascade 2 pairs o 3 cells). Possibly using a circulation pump, although it would probably circulate with the gas flow, like the dry cells do. (Although I believe mesh electrode cells work best with a pump).

Both cars will have a 30-40amp PWM supply (mounted under bonnet) with the variable resistor remote-mounted inside the car next to a digital volt/amp display (all cheap on eBay from Hong Kong/China), protected under the bonnet with a 30 or 40 amp circuit breaker & use the ultimate strength of KOH (or NaOH) in distilled water, as gained from Patrick Kelly's eBooks (I think it's 28% KOH by weight). All this is in order to get the best efficiency from the cells.

Plates will be cross sanded & cleaned. Also might do the magnetic alignment thing with a battery & some wire. I will also try to condition the cells (again, as stated in Patrick Kelly's eBooks).

OK, I think that's about it. Can anyone see any massive issues here? Am I being stupid anywhere? (it has been known, but go easy on me).

Oh yes, I'm based in the UK (south east), which is why I use a combination of imperial & metric measurements & why I buy my electronics from China on eBay.

Am I just making things more complicated with my flooded wet cell design?? Should I just build dry cells & stop mucking about??? It's just I think a good wet cell design should out perform a dry cell due to the lack of current bypassing places between the plates (I know they will be joined by the pipes, which will allow some current to low through the electrolyte, but these could have non-return valves & be coiled to put more length, & therefore more electrical resistance, in the line, which should be negligible compared to the dry cells), but everyone seems set on dry cells these days.

So, any thoughts on stainless steel mesh electrodes (in wet cells)???

Does anyone use a circulation pump on their dry cells???

Any gasket materials to avoid???

Should I have posted this somewhere else??? (& please don't say "Yes, on another web forum!")

I also plan to use an ultrasonic cold water mist machine to add a cold water mist into the intake, this alone should yield some MPG gains. (cold water mist good, steam bad).

OK that's enough! Too many questions, I will stop now. Any thoughts anyone?